/**
 * Copyright (c) 2005-2010 wwinsoft.org.cn
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 *
 * $Id: HibernateDao.java 1205 2010-09-09 15:12:17Z calvinxiu $
 */
package com.wwinsoft.modules.orm.hibernate;

import org.apache.commons.lang.StringUtils;
import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.SessionFactory;
import org.hibernate.criterion.*;
import org.hibernate.impl.CriteriaImpl;
import org.hibernate.transform.ResultTransformer;
import org.springframework.util.Assert;
import com.wwinsoft.modules.orm.Page;
import com.wwinsoft.modules.orm.PropertyFilter;
import com.wwinsoft.modules.utils.reflection.ReflectionUtils;

import java.io.Serializable;
import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * 封装SpringSide扩展功能的Hibernat DAO泛型基类.
 * <p/>
 * 扩展功能包括分页查询,按属性过滤条件列表查询.
 * 可在Service层直接使用,也可以扩展泛型DAO子类使用,见两个构造函数的注释.
 *
 * @author calvin
 * @param <T> DAO操作的对象类型
 * @param <PK> 主键类型
 */
public class HibernateDao<T, PK extends Serializable> extends SimpleHibernateDao<T, PK> {
    /**
     * 用于Dao层子类的构造函数.
     * 通过子类的泛型定义取得对象类型Class.
     * eg.
     * public class UserDao extends HibernateDao<User, Long>{
     * }
     */
    public HibernateDao() {
        super();
    }

    /**
     * 用于省略Dao层, Service层直接使用通用HibernateDao的构造函数.
     * 在构造函数中定义对象类型Class.
     * eg.
     * HibernateDao<User, Long> userDao = new HibernateDao<User, Long>(sessionFactory, User.class);
     */
    public HibernateDao(final SessionFactory sessionFactory, final Class<T> entityClass) {
        super(sessionFactory, entityClass);
    }

    //-- 分页查询函数 --//

    /**
     * 分页获取全部对象.
     */
    public Page<T> getAll(final Page<T> page) {
        return findPage(page);
    }

    /**
     * 按HQL分页查询.
     *
     * @param page   分页参数. 注意不支持其中的orderBy参数.
     * @param hql    hql语句.
     * @param values 数量可变的查询参数,按顺序绑定.
     * @return 分页查询结果, 附带结果列表及所有查询输入参数.
     */
    @SuppressWarnings("unchecked")
    public Page<T> findPage(final Page<T> page, final String hql, final Object... values) {
        Assert.notNull(page, "page不能为空");

        Query q = createQuery(hql, values);

        if (page.isAutoCount()) {
            long totalCount = countHqlResult(hql, values);
            page.setTotalCount(totalCount);
        }

        setPageParameterToQuery(q, page);

        List result = q.list();
        page.setResult(result);
        return page;
    }

    /**
     * 按HQL分页查询.
     *
     * @param page   分页参数. 注意不支持其中的orderBy参数.
     * @param hql    hql语句.
     * @param values 命名参数,按名称绑定.
     * @return 分页查询结果, 附带结果列表及所有查询输入参数.
     */
    @SuppressWarnings("unchecked")
    public Page<T> findPage(final Page<T> page, final String hql, final Map<String, ?> values) {
        Assert.notNull(page, "page不能为空");

        Query q = createQuery(hql, values);

        if (page.isAutoCount()) {
            long totalCount = countHqlResult(hql, values);
            page.setTotalCount(totalCount);
        }

        setPageParameterToQuery(q, page);

        List result = q.list();
        page.setResult(result);
        return page;
    }

    @SuppressWarnings("unchecked")
    public Page<T> findSQLPage(final Page<T> page, final String sql, final Map<String, ?> values) {
        Assert.notNull(page, "page不能为空");

        if (page.isAutoCount()) {
            long totalCount = countSqlResult(sql, values);
            page.setTotalCount(totalCount);
        }

        Query q = createSQLQuery(setPageOrderToSQL(sql, page), values);

        setPageParameterToQuery(q, page);

        List result = q.list();
        page.setResult(result);
        return page;
    }

    /**
     * 按Criteria分页查询.
     *
     * @param page       分页参数.
     * @param criterions 数量可变的Criterion.
     * @return 分页查询结果.附带结果列表及所有查询输入参数.
     */
    @SuppressWarnings("unchecked")
    public Page<T> findPage(final Page<T> page, final Criterion... criterions) {
        Assert.notNull(page, "page不能为空");

        Criteria c = createCriteria(criterions);

        if (page.isAutoCount()) {
            long totalCount = countCriteriaResult(c);
            page.setTotalCount(totalCount);
        }

        setPageParameterToCriteria(c, page);

        List result = c.list();
        page.setResult(result);
        return page;
    }

    /**
     * 设置分页参数到Query对象,辅助函数.
     */
    protected Query setPageParameterToQuery(final Query q, final Page<T> page) {

        Assert.isTrue(page.getPageSize() > 0, "Page Size must larger than zero");

        //hibernate的firstResult的序号从0开始
        q.setFirstResult(page.getFirst() - 1);
        q.setMaxResults(page.getPageSize());
        return q;
    }

    protected String setPageOrderToSQL(final String sql, final Page<T> page ) {
        if (page.isOrderBySetted()) {
            String[] orderByArray = StringUtils.split(page.getOrderBy(), ',');
            String[] orderArray = StringUtils.split(page.getOrder(), ',');

            Assert.isTrue(orderByArray.length == orderArray.length, "分页多重排序参数中,排序字段与排序方向的个数不相等");

            StringBuilder sb = new StringBuilder();
            sb.append(sql);
            sb.append(" order by ");
            for (int i = 0; i < orderByArray.length; i++) {
                if (Page.ASC.equals(orderArray[i])) {
                    sb.append(orderByArray[i]).append(" ").append(Page.ASC);
                } else {
                    sb.append(orderByArray[i]).append(" ").append(Page.DESC);
                }
                if(i!=orderByArray.length-1){
                    sb.append(",");
                }
            }
            return sb.toString();
        }
        return sql;
    }

    /**
     * 设置分页参数到Criteria对象,辅助函数.
     */
    protected Criteria setPageParameterToCriteria(final Criteria c, final Page<T> page) {

        Assert.isTrue(page.getPageSize() > 0, "Page Size must larger than zero");

        //hibernate的firstResult的序号从0开始
        c.setFirstResult(page.getFirst() - 1);
        c.setMaxResults(page.getPageSize());

        if (page.isOrderBySetted()) {
            String[] orderByArray = StringUtils.split(page.getOrderBy(), ',');
            String[] orderArray = StringUtils.split(page.getOrder(), ',');

            Assert.isTrue(orderByArray.length == orderArray.length, "分页多重排序参数中,排序字段与排序方向的个数不相等");

            for (int i = 0; i < orderByArray.length; i++) {
                if (Page.ASC.equals(orderArray[i])) {
                    c.addOrder(Order.asc(orderByArray[i]));
                } else {
                    c.addOrder(Order.desc(orderByArray[i]));
                }
            }
        }
        return c;
    }

    /**
     * 执行count查询获得本次Hql查询所能获得的对象总数.
     * <p/>
     * 本函数只能自动处理简单的hql语句,复杂的hql查询请另行编写count语句查询.
     */
    protected long countHqlResult(final String hql, final Object... values) {
        String countHql = prepareCountHql(hql);

        try {
            Long count = findUnique(countHql, values);
            return count;
        } catch (Exception e) {
            throw new RuntimeException("hql can't be auto count, hql is:" + countHql, e);
        }
    }

    /**
     * 执行count查询获得本次Hql查询所能获得的对象总数.
     * <p/>
     * 本函数只能自动处理简单的hql语句,复杂的hql查询请另行编写count语句查询.
     */
    protected long countHqlResult(final String hql, final Map<String, ?> values) {
        String countHql = prepareCountHql(hql);

        try {
            Long count = findUnique(countHql, values);
            return count;
        } catch (Exception e) {
            throw new RuntimeException("hql can't be auto count, hql is:" + countHql, e);
        }
    }

    protected long countSqlResult(final String hql, final Map<String, ?> values) {
        String countHql = prepareCountHql(hql);

        try {
            BigDecimal count = (BigDecimal)createSQLQuery(countHql, values).uniqueResult();
            return count.longValue();
        } catch (Exception e) {
            throw new RuntimeException("Sql can't be auto count, hql is:" + countHql, e);
        }
    }

    private String prepareCountHql(String orgHql) {
        String fromHql = orgHql;
        //select子句与order by子句会影响count查询,进行简单的排除.
        fromHql = "from " + StringUtils.substringAfter(fromHql, "from");
        fromHql = StringUtils.substringBefore(fromHql, "order by");

        String countHql = "select count(*) " + fromHql;
        return countHql;
    }

    private String prepareCountSql(String orgHql) {
        String fromHql = orgHql;
        //select子句与order by子句会影响count查询,进行简单的排除.
        fromHql = "from " + StringUtils.substringAfter(fromHql, "from");
        fromHql = StringUtils.substringBefore(fromHql, "order by");

        String countHql = "select count(*) " + fromHql;
        return countHql;
    }

    /**
     * 执行count查询获得本次Criteria查询所能获得的对象总数.
     */
    @SuppressWarnings("unchecked")
    protected long countCriteriaResult(final Criteria c) {
        CriteriaImpl impl = (CriteriaImpl) c;

        // 先把Projection、ResultTransformer、OrderBy取出来,清空三者后再执行Count操作
        Projection projection = impl.getProjection();
        ResultTransformer transformer = impl.getResultTransformer();

        List<CriteriaImpl.OrderEntry> orderEntries = null;
        try {
            orderEntries = (List) ReflectionUtils.getFieldValue(impl, "orderEntries");
            ReflectionUtils.setFieldValue(impl, "orderEntries", new ArrayList());
        } catch (Exception e) {
            logger.error("不可能抛出的异常:{}", e.getMessage());
        }

        // 执行Count查询
        Long totalCountObject = (Long) c.setProjection(Projections.rowCount()).uniqueResult();
        long totalCount = (totalCountObject != null) ? totalCountObject : 0;

        // 将之前的Projection,ResultTransformer和OrderBy条件重新设回去
        c.setProjection(projection);

        if (projection == null) {
            c.setResultTransformer(CriteriaSpecification.ROOT_ENTITY);
        }
        if (transformer != null) {
            c.setResultTransformer(transformer);
        }
        try {
            ReflectionUtils.setFieldValue(impl, "orderEntries", orderEntries);
        } catch (Exception e) {
            logger.error("不可能抛出的异常:{}", e.getMessage());
        }

        return totalCount;
    }

    //-- 属性过滤条件(PropertyFilter)查询函数 --//

    /**
     * 按属性查找对象列表,支持多种匹配方式.
     *
     * @param matchType 匹配方式,目前支持的取值见PropertyFilter的MatcheType enum.
     */
    public List<T> findBy(final String propertyName, final Object value, final PropertyFilter.MatchType matchType) {
        Criterion criterion = buildCriterion(propertyName, value, matchType);
        return find(criterion);
    }

    /**
     * 按属性过滤条件列表查找对象列表.
     */
    public List<T> find(List<PropertyFilter> filters) {
        Criterion[] criterions = buildCriterionByPropertyFilter(filters);
        return find(criterions);
    }

    public List<T> findDetached(List<PropertyFilter> filters) {
        ResolveAlias ra = new ResolveAlias();
        DetachedCriteria detachedCriteria = buildDetachedCriteriaByPropertyFilter(filters,ra);
        return detachedCriteria.getExecutableCriteria(getSession()).list();
    }

    /**
     * 按属性过滤条件列表分页查找对象.
     */
    public Page<T> findPage(final Page<T> page, final List<PropertyFilter> filters) {
        Criterion[] criterions = buildCriterionByPropertyFilter(filters);
        return findPage(page, criterions);
    }

    public Page<T> findDetachedPage(final Page<T> page, final List<PropertyFilter> filters) {
        ResolveAlias ra = new ResolveAlias();
        DetachedCriteria detachedCriteria = buildDetachedCriteriaByPropertyFilter(filters,ra);

        if (page.isOrderBySetted()) {
            String[] orderByArray = StringUtils.split(page.getOrderBy(), ',');
            List<String>  orderByArrayNew = new ArrayList<String>();

            for (int i = 0; i < orderByArray.length; i++) {
                String orderByNew = getRealPropertyName(orderByArray[i],ra);
                orderByArrayNew.add(orderByNew);
            }
            page.setOrderBy( StringUtils.join(orderByArrayNew,','));
        }

        Criteria c =  detachedCriteria.getExecutableCriteria(getSession());
        if (page.isAutoCount()) {
            long totalCount = countCriteriaResult(c);
            page.setTotalCount(totalCount);
        }

        setPageParameterToCriteria(c, page);

        List result = c.list();
        page.setResult(result);
        return page;
    }

    /**
     * 按属性条件参数创建Criterion,辅助函数.
     */
    protected Criterion buildCriterion(final String propertyName, final Object propertyValue, final PropertyFilter.MatchType matchType) {
        Assert.hasText(propertyName, "propertyName不能为空");
        Criterion criterion = null;
        //根据MatchType构造criterion
        switch (matchType) {
            case EQ:
                criterion = Restrictions.eq(propertyName, propertyValue);
                break;
            case LIKE:
                criterion = Restrictions.like(propertyName, (String) propertyValue, MatchMode.ANYWHERE);
                break;

            case LE:
                criterion = Restrictions.le(propertyName, propertyValue);
                break;
            case LT:
                criterion = Restrictions.lt(propertyName, propertyValue);
                break;
            case GE:
                criterion = Restrictions.ge(propertyName, propertyValue);
                break;
            case GT:
                criterion = Restrictions.gt(propertyName, propertyValue);
        }
        return criterion;
    }

    /**
     * 按属性条件列表创建DetachedCriteria,辅助函数.
     */
    protected DetachedCriteria buildDetachedCriteriaByPropertyFilter(final List<PropertyFilter> filters ,ResolveAlias ra) {
        DetachedCriteria detachedCriteria = DetachedCriteria.forClass(entityClass);
        if (filters != null || filters.size() > 0) {
            ra.setDca(detachedCriteria);
            for (PropertyFilter propertyFilter : filters) {
                String propertyName = propertyFilter.getPropertyName();
                String realPropertyName = getRealPropertyName(propertyName, ra);
                detachedCriteria.add(buildCriterion(realPropertyName, propertyFilter.getMatchValue(), propertyFilter.getMatchType()));
            }
        }
        // 去重复
        detachedCriteria.setResultTransformer(CriteriaSpecification.DISTINCT_ROOT_ENTITY);
        return detachedCriteria;
    }

    private String getRealPropertyName(String propertyName, ResolveAlias ra) {
        if (propertyName.indexOf(".") == -1) {
            //单值属性或日期
            return propertyName;
        } else {
            //关联对象
            String association = StringUtils.substringBeforeLast(propertyName, ".");
            String property = StringUtils.substringAfterLast(propertyName, ".");
            String aliasName = ra.createAlias(association);
            return aliasName + "." + property;
        }
    }

    /**
     * 按属性条件列表创建Criterion数组,辅助函数.
     */
    protected Criterion[] buildCriterionByPropertyFilter(final List<PropertyFilter> filters) {
        List<Criterion> criterionList = new ArrayList<Criterion>();
        for (PropertyFilter filter : filters) {
            if (!filter.hasMultiProperties()) { //只有一个属性需要比较的情况.
                Criterion criterion = buildCriterion(filter.getPropertyName(), filter.getMatchValue(), filter
                        .getMatchType());
                criterionList.add(criterion);
            } else {//包含多个属性需要比较的情况,进行or处理.
                Disjunction disjunction = Restrictions.disjunction();
                for (String param : filter.getPropertyNames()) {
                    Criterion criterion = buildCriterion(param, filter.getMatchValue(), filter.getMatchType());
                    disjunction.add(criterion);
                }
                criterionList.add(disjunction);
			}
		}
		return criterionList.toArray(new Criterion[criterionList.size()]);
	}
}
